Cortical mechanisms related to the direction of two-dimensional arm movements: relations in parietal area 5 and comparison with motor cortex

J. F. Kalaska, R. Caminiti, A. P. Georgopoulos

Research output: Contribution to journalArticlepeer-review

320 Scopus citations

Abstract

The relations between the direction of two-dimensional arm movements and single cell discharge in area 5 were investigated during 49 penetrations into the superior parietal lobule of 3 monkeys. A significant variation of cell discharge with the direction of movement was observed in 182 of 212 cells that were related to arm movements. In 151/182 of these cells the frequency of discharge was highest during movements in a preferred direction, and decreased in an orderly fashion with movements made in directions farther and farther away from the preferred one; in 112/151 cells this variation in discharge was a sinusoidal function of the direction of movement. Preferred directions differed for different cells so that directional tuning curves overlapped partially. These results are similar to those described for cells in the motor cortex (Georgopoulos et al. 1982): this suggests that directional information may be processed in a similar way in these structures. Many cells in area 5 changed activity before the onset of movement, and several did so before the earliest electromyographic changes (63% and 35%, respectively, of the cells that showed an increase in activity with movements in the preferred direction). However, the distribution of onset times of the parietal cells lagged the corresponding one of the motor cortical cells by about 60 ms. This suggests that the early changes observed in the parietal cortex might represent a corollary discharge from the pre-central motor fields, whereas later activity might reflect peripheral as well as central events.

Original languageEnglish (US)
Pages (from-to)247-260
Number of pages14
JournalExperimental Brain Research
Volume51
Issue number2
DOIs
StatePublished - Jul 1983

Keywords

  • Cortex
  • Direction
  • Motor
  • Movement
  • Parietal

Fingerprint

Dive into the research topics of 'Cortical mechanisms related to the direction of two-dimensional arm movements: relations in parietal area 5 and comparison with motor cortex'. Together they form a unique fingerprint.

Cite this